1. Home
  2. Studebaker Autos
  3. Confused by Stude 2-wire fuel gauge system

Confused by Stude 2-wire fuel gauge system

When I fixed my fuel tank the gas gauge stopped working and now is always below empty. The sender had been in really bad shape so I assumed that was the problem (me and my assumptions). Before dropping the tank I hooked up the new sender to verify it is working and found that the gauge is still DOA. I am trying to troubleshoot but I don't really understand how the two-wire system Studebaker used works. I have never seen a sender that did not use ground for the reference and so far I have found nothing searching the web or my books. Why was it done this way? The only reason I can think of is to somehow "balance" the gauge so it does not vary with the system voltage.

I have verified that the tank and sender body are both grounded. Of the two wires one is putting out a full 6V and the other does about 2.5V. I get almost the same voltages on the back of the gauge so I am pretty sure the wires are good. I am beginning to suspect I fried the gauge somehow. Does anyone know the way this is supposed to work?

Here is my web page covering the sender:

formatting link
Thanks!

Reply to
NAV
Loading thread data ...

sender:

formatting link

I did you that you've done including dissembly, cleaning, extra ground wires and even a NOS gauge mine - all to no avail. I finally tweaked the wiper a tad to increase it's pressure on the resister. When I bench tested it - it worked - but it would not work installed in my truck. In the midst of my 30th trial and error test I stopped for dinner. When I came back the gauge was working! Before dinner I had hooked up only the center-most wire. All attempts to add the 2nd wire seemed to kill gauge. I taped it out of the way and my gas gauge and I have been happy ever since.

Wayne Lee

52 2R5
Reply to
wayne.lee

If I remember correctly the sending unit(s) measure the resistance. Adding a second ground would defeat it. From what I was told, there is constant voltage going thru the sender. basically the gauge is a VOM reader. I do not remember which way it reads though. More resistance, more fuel or vice versa.

I liked the fuel gauge in my old J-3 much better, a cork on an end of a coat hanger wire. The more wire you saw, the more gas was in the tank. When no wire showed.......SOL.

BG

Reply to
Bill Glass

Testing and wiring is in the 1941-42 Shop Manual if you have that available.

Reply to
Dwain G.

I have the shop manual but it only shows the wiring diagram which does not have enough detail for me to figure this out. I have been trying to avoid disconnecting wires behind the dash but that is probably the next step. If I could just get the gauge to move then at least I will have isolated the problem a little.

I may have missed a troubleshooting section in the manual. I will look again.

Reply to
NAV

I was referring to page 49, in the 'Gasoline System' section. It also appears in the 2R truck manual.

Reply to
Dwain G.

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.